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The Python language has two kind of functions — normal functions that you would use in most cases, and async functions. The latter functions are used when performing network IO in an asynchronous manner. The problem with this division is that async functions can only be called from other async functions. Normal functions, on the other hand, can be called from any functions — however, if you call a normal function that does a blocking operation from an async function, it will block the whole event loop and all your coroutines. These limitations usually mean that when writing an using Python`s asyncio, you can`t use any of the IO libraries that you use when writing a synchronous application, and vice versa, unless a library supports usage both in sync and async applications.

Now, the question is, in case you are developing a large and complex library, that, say, allows users to interact with relational databases, abstracting away (some of) the differences between the SQL syntax and other aspects of these databases, and abstracting away the differences between the drivers for that database, how do you support both sync and async usage of your library without duplicating the code of your library? The way sqlalchemy is organized is that regardless of what database and driver for it you are using, you will be calling functions and methods related to Engine, Connection, etc classes, which will do some general work independent of database, then apply the logic specific to your database and finally, call the functions of your database driver to actually communicate with the database. If you are using Python`s asyncio, the database driver will expose async functions and methods, but the rest of the library that is driver‑independent would ideally remain the same. However, the issue is that that you can`t call the async functions of the driver from the normal functions of the core of the library.

Surprisingly, there are strict mathematical methods that literally allow to hear visual geometric forms and, conversely, to see the beauty of musical harmonies...

[Read on Russian]

One of the significant advantages of this custom hook is that it ensures the callback function remains up to date even if it changes during component re-renders. By using a useRef to store the callback reference, the hook guarantees that the latest version of the function is always called.

Hello, everyone! In this post, let's talk about how to (more) accurately measure the dynamic range of a camera sensor and what can be done with these measurements.

Of course, I am not an expert in computer vision, a programmer or a statistician, so please feel free to correct me in the comments if I make mistakes in this post. Here my interest was primarily focused on everyday and practical tasks, such as photography, but I believe the results may also be useful to computer vision professionals.

In our last article we covered the anatomy of a presale meeting gone wrong. In that article we posed some questions for everyone to think about. What exactly does an American company wanting to hire a Russian custom software development company, feel about this Russian company? What are they afraid of? What are their concerns?

In the end we came up with five concerns.

1. Is the company a fly by night company, is the company a one-day company?

2. Will they be professional in supporting or developing the software that they've sold to us?

3. Will they have proper data security?

And now the two new ones that are because of the mess the world is in now...

4. Will they be able to complete the project on time? This includes proper internet access an infrastructure to support IT.

5. Where is your team located? Are you still located in Russia?

Now we're going to look at the last 2, number four and five.
However let's look at number 5 first.

Many IT companies today if they want to work with the United States or even Europe they must not have their developers located inside of Russia. Matter of fact it goes so far that if a developer is located in Russia and they're using a VPN and somehow the VPN is breached the credentials are canceled for that developer to work on the project.

It's for this reason that Russian IT companies are opening offices around the world. Let's look at Armenia as an example.

Wait a minute I have to go back for a second...... We must discuss how countries look to America Canada and Western Europe. I basically give them a score based on questions that are brought up in the mind of the American company or European company.

One of the key advantages of this custom hook is its simplicity. You can use it to store any type of data, such as strings, numbers, or even complex objects, with just a few lines of code. Additionally, useStorage handles the serialization and deserialization of data for you, so you don't have to worry about converting values to and from JSON.

In Part 1, we became familiar with the concept of entropy.

In this part, we will delve into the concept of Mutual Information, which opens doors to error-resistant coding, compression algorithms, and offers a fresh perspective on regression and Machine Learning tasks.

It is an essential component that will pave the way, in the next section, for tackling Machine Learning problems as tasks of extracting mutual information between features and the predicted variable.

Here, there will be three interesting and crucial visualizations.

The first one will visualize entropy for two random variables and their mutual information.
The second one will shed light on the very concept of dependency between two random variables, emphasizing that zero correlation does not imply independence.
The third one will demonstrate that the bandwidth of an information channel has a straightforward geometric interpretation through the convexity measure of the entropy function.

In the meantime, we will prove a simplified version of the Shannon-Hartley theorem regarding the maximum bandwidth of a noisy channel. Let's dive in!

In my just released game “Protolife: Other Side” I have the destructible landscape. Creatures that we control can make new ways through the walls. Also, some enemies are able to modify the landscape as well.

Let me describe how it may be done on the Godot engine.

Product management runs on choices. What to develop next, what to put on hold, and what to discard altogether. Getting these choices right steers products toward success. It's more than just a list; it's understanding needs, managing resources, and aligning with the company vision. Prioritization is, without a doubt, a major skill for any product manager.

For most of us, the daily challenge is juggling plenty of tasks, features, and stakeholder requests. But not all demands carry the same weight. It's easy to get swayed by the loudest voice in the room or the most recent email in the inbox, but these aren't necessarily what the product or the users need most urgently.

To get it right in product management, we need the right tools and approaches. Let's see what it takes to nail prioritization.

Key challenges in prioritization

As I noted before, in product management, facing various and often unpredictable challenges is part of the job. However, deciding which tasks to prioritize can be especially confusing, and here are a few factors to consider.

1. Changing customer demands: Customers are the heart of any product, and their needs and desires can evolve rapidly. One day, a feature might be all the rage; the next, it's old news. For instance, a messaging app might find its users clamoring for dark mode due to its increasing popularity across platforms. Adapting to these shifting demands requires constant observation and a readiness to pivot.

2. Evolving market trends: The broader market can influence product decisions as much as individual user feedback. If there's a sudden surge in voice-activated technologies, products that don't incorporate voice features might find themselves left behind. Staying attuned to the market means continuous research and the agility to tweak your product roadmap accordingly.

We released the new version of Chipmunk, software for viewing/analyzing log files. V.3 is wholly reworked with an accent to performance and rethought considering usability. Below short list of the most important changes and a general description.

One of the key advantages of this custom hook is its flexibility. You can pass any validation function that suits your specific requirements. Whether it's checking the length of a string, ensuring a numeric value falls within a certain range, or performing more complex validations, useStateWithValidation has got you covered.

My name is Paul Karol and I work connecting Russian IT with their customers in the United States. Please find on Hbar my previous article for a complete explanation of my credentials.

Today we're going to look at a presale meeting that was not successful and we will explain exactly how the Russian company lost this business. Please take a look at this photograph.

Going into this presale meeting the client (large American chain store) had worked with the software for a little more than a month and we're pretty happy with the result. From all indications they were going to buy the software this day. The sales manager had a good relationship with the American managers of the company. There was lots of buying sign that was known to the Russian company prior to this presale meeting. Suffice to say that they believe that they would have an easy sale today.

There was some very specific things that the Russians did that cost them this business.

We will be using this as a case study and we will discuss exactly everything that they did as a mistake and how to not do these same mistakes for your company.

First we must do some brain work. A thought experiment, if you will. What do you believe are the concerns of an American company doing business with Russian IT developers today. The current situation between the countries does make it more difficult but the same exact concerns are still there from before maybe slightly more amplified and there may be one more concern that wasn't there prior to the difficulties in Ukraine.

In this article series, we embark on a journey through the realm of custom React hooks, discovering their immense potential for elevating your development projects. Our focus today is on the "useStateWithHistory" hook, one of the many carefully crafted hooks available in the collection of React custom hooks.

Hello, dear users of the IT world!

In the era of active development of web technologies and interactive applications, 3D-graphics is becoming more and more relevant and in demand. But how to create a 3D application without losing the advantages of web development? In this article, we will look at how to combine the power of Three.js with the flexibility of React to create your own game right in the browser.

This article will introduce you to the React Three Fiber library and teach you how to create interactive 3D games.

useScript can be used in various scenarios. For instance, you can load external libraries like jQuery, enabling you to harness its powerful functionalities without adding bulk to your bundle. Additionally, you can load analytics scripts, social media widgets, or any other script necessary for your application's dynamic behavior.

I've long wanted to create educational materials on the topic of Information Theory + Machine Learning. I found some old drafts and decided to polish them up here, on Habr.

Information Theory and Machine Learning seem to me like an interesting pair of fields, the deep connection between which is often unknown to ML engineers, and whose synergy has not yet been fully revealed.

Let's start with basic concepts like Entropy, Information in a message, Mutual Information, and channel capacity. Next, there will be materials on the similarity between tasks of maximizing Mutual Information and minimizing Loss in regression problems. Then there will be a section on Information Geometry: Fisher metric, geodesics, gradient methods, and their connection to Gaussian processes (moving along the gradient using SGD is moving along the geodesic with noise).

It's also necessary to touch upon AIC, Information Bottleneck, and discuss how information flows in neural networks – Mutual Information between layers (Information Theory of Deep Learning, Naftali Tishby), and much more. It's not certain that I'll be able to cover everything listed, but I'll try to get started.

One of the major advantages of using useRenderCount is its simplicity. By abstracting the logic into a reusable hook, you can easily integrate it into any component without cluttering your codebase. Additionally, it provides a clear and concise way to monitor render behavior, which can be crucial for performance optimization and debugging.

This custom hook can be a game-changer in various scenarios. For instance, you can utilize usePrevious to compare and visualize changes in data, track state transitions, or implement undo/redo functionality. Additionally, it can be valuable in form handling, animations, and any situation where having access to the previous value is crucial for your application's logic.

The intuition is to employ a depth-first search (DFS) approach through the tree.

During each step in the traversal, we perform the following key calculations:

1. Determine the path that ends at the current node.

2. Compute two different subtree paths that traverse the current node.

3. Maintain an array that keeps track of the cases where paths contain either 0 or 1 prime number.

This method allows us to efficiently count the valid paths in the tree while considering the presence of prime numbers.

Hello, dear users of the IT world!

In modern web development there are many ways to make your website interesting and attractive to users. And even using simple techniques you can achieve great results!

I suggest you to create a mini-game from scratch yourself. And then, you can use it to liven up and add interactivity to any web page.